Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 145/80-18 | 145/40-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.13 (689.2) | 22.57 (573.2) | -4.57 (-116) -16.8% |
| Width inches (mm) | 5.71 (145) | 5.71 (145) | 0 (0) 0% |
| Circum. inches (mm) | 85.24 (2165.19) | 70.9 (1800.76) | -14.35 (-364.42) -16.8% |
| Sidewall Height inches (mm) | 4.57 (116) | 2.28 (58) | -2.28 (-58) -50% |
| Revolutions per mile (km) | 743.28 (461.85) | 893.7 (555.32) | 150.42 (93.47) 20.2% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 16.63 mph (26.77 km/h) |
| 25 mph (40.23 km/h) | 20.79 mph (33.46 km/h) |
| 30 mph (48.28 km/h) | 24.95 mph (40.15 km/h) |
| 35 mph (56.33 km/h) | 29.11 mph (46.85 km/h) |
| 40 mph (64.37 km/h) | 33.27 mph (53.54 km/h) |
| 45 mph (72.42 km/h) | 37.43 mph (60.23 km/h) |
| 50 mph (80.47 km/h) | 41.58 mph (66.92 km/h) |
| 55 mph (88.51 km/h) | 45.74 mph (73.62 km/h) |
| 60 mph (96.56 km/h) | 49.9 mph (80.31 km/h) |
| 65 mph (104.61 km/h) | 54.06 mph (87 km/h) |
| 70 mph (112.65 km/h) | 58.22 mph (93.69 km/h) |
| 75 mph (120.7 km/h) | 62.38 mph (100.39 km/h) |
| 80 mph (128.75 km/h) | 66.54 mph (107.08 km/h) |
| 85 mph (136.79 km/h) | 70.69 mph (113.77 km/h) |
| 90 mph (144.84 km/h) | 74.85 mph (120.46 km/h) |
| 95 mph (152.89 km/h) | 79.01 mph (127.16 km/h) |
| 100 mph (160.93 km/h) | 83.17 mph (133.85 km/h) |
| 2.35 | 2.73 | 2.94 | 3.07 | 3.21 | 3.31 | 3.42 | 3.55 | 3.73 | 3.91 | 4.11 | 4.27 | 4.56 | 4.88 | 5.13 | 5.29 | 5.38 | 5.71 | 6.17 | 7.17 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2274 | 2642 | 2845 | 2971 | 3107 | 3203 | 3310 | 3436 | 3610 | 3784 | 3978 | 4132 | 4413 | 4723 | 4965 | 5120 | 5207 | 5526 | 5971 | 6939 |
Better Fuel Economy Factory Ratios Increased Power
